Sander plate assembly for portable sanding tools



Sept. 24, 1963 J. P. YELPO ETAL 3,104,503

SANDER PLATE ASSEMBLY FOR PORTABLE SANDING TOOLS Filed Jan. 9, 1961 2Sheets-Sheet l INVENTORS Joseph P. Yelpo WITNESS Joseph J. RomanoATTORNEY Sept. 24, 1963 J. P. YELPO ETAL SANDER PLATE ASSEMBLY FORPORTABLE SANDING TOOLS Filed Jan. 9, 1961 2 Sheets$heet 2 Fig.3

I 24 i I 20 II E i 23 w I0 I F|g.4 l3 I Fig.5

INVENTORS Joseph P. Yelpo Joseph J. Romano WITNESS BY 4 K a ZTTORNEYUnited States Patent 3,104,503 SANDER PLATE ASSELY FOR PORTABLE SANDLNGTOOLS Joseph P. Yelpo, Greenville, S.C., and Joseph J. Romano,

South River, N.J., assignors to The Singer Company,

a corporation of New Jersey Filed Jan. 9, 1961, Ser. No. 81,588 1 Claim.(Cl. 51189) This invention relates to a sander plate assembly for aportable sanding tool and more particularly to means associatedtherewith for releasably clamping abrasive sheets.

It is an object of this invention to provide a sander plate assemblyhaving simple but effective means for releasably clamping abrasivesheets.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations and arrangements ofpar-ts hereinafter set forth and illustrated in the accompanyingdrawings of a preferred embodiment of the invention, from which theseveral features of the invention and the advantages attained therebywill be readily understood by those skilled in the art.

In the drawing,

FIG. 1 is a plan view of a sander plate embodying the invention.

FIG. 2 is an elevational view, partly in section, of the device of FIG.1.

FIG. 3 is a fragmentary plan view of the device of FIG. 1 showing theparts in a specific operating condition.

FIG. 4 is an elevational view of the parts shown in FIG. 3.

FIG. 5 is an exploded view showing details of the cam and leverassembly.

Referring now to FIG. 1, a flat rectangular base has struck-up lugportions 11 and 12 forming means for securing the base to a driving toolbody (not shown). A rubber pad 13 is cemented to the bottom of the base10 to serve as a cushion for an abrasive sheet which is releasably heldagainst the pad 13 by means to be described.

At each end of the base 10 and secured to the top side thereof by meansof rivets 15 is a leaf spring means 16 enlarged at the free end and bentto form a clamp portion 17. A transverse stiffening rib 18 is formed inthe material in the clamp portion to provide lateral stiffness and acentral aperture 19 is provided, through which extends a lever-operatedcam 20.

The cam 20, as best seen in FIG. 5, is preferably formed from a singlepiece by bending to provide a lever portion 21, a cam portion 22 and abody pontion 23 which latter embraces a pin 24 secured to the base 10 asby riveting. The pin 24 stands with its axis positioned normally to thebase 10 and extending upward through the central aperture 19 as shown.

In the position of the parts as shown in FIGS. 1 and 2, the leaf springmeans 16 is normally warped to stand with the clamp portion 17 thereofspaced away from the base 10 to form a gap for insertion of the abrasivesheet 14. Clamping of the abrasive sheet is effected by rotation of thelever-operated cam 20 about the pin 24 from the position shown in FIGS.1 and 2 to the position shown in FIGS. 3 and 4. As the lever 21 isturned, the cam portion 22 first engages a depressed portion 25 of theleaf spring means. Further rotation of the lever 21 earns the clampportion 17 of the leaf spring means 16 downward toward the base 10until, in the position shown in FIGS. 3 and 4, the abrasive sheet 14 issecurely but resiliently clamped between the clamp portion 17 and thebase 10.

Removal of the abrasive sheet is eiiected by reversing the proceduredescribed above.

Having thus set forth the nature of this invention, what we claim hereinis:

A sander plate assembly for a portable sanding tool adapted to receiveabrasive sheets comprising a base, leaf spring means secured at one endto said base and normally warped to stand at the other end with a clampportion spaced away from said base to form a gap for insertion of saidabrasive sheet, said leaf spring means having a centrally aperturedportion, and lever-operated cam means positioned on said base to swingabout an axis normal to said base and projecting through said aperturedportion to urge said clamp portion to engage said abrasive sheet inclamping relation with the base.

References Cited in the file of this patent UNITED STATES PATENTS2,251,329 Ekstrom Aug. 5, 1941 2,428,618 Dispensiere Oct. 7, 19472,464,296 Ekstrom Mar. 15, 1949 2,509,561 Dremel May 30, 1950 2,530,301Hoy Nov. 14, 1950

